The subject of No Greater Love (World Service) sounded slight at first. "An unassuming monument in a tucked away park," explained presenter Cathy FitzGerald. She had stumbled on Postman's Park one morning and found "one of London's secrets": a curious memorial to people who lost their lives in self-sacrifice.

But this beautifully made feature – produced by Matt Thompson for Rockethouse – quietly packed a hefty emotional punch as it went on. After describing the monument, with its tiles for each individual it commemorates, the programme focused on a much more recent story: the death of Leigh Pitt in 2007, who died while saving a child from drowning in a canal. We heard from his girlfriend, who saw the whole thing, and the police officer who jumped in to try to save Pitt.

Their recollections, and reflections on that day, were simply told and very powerful. "I actually made the decision to save myself," the police officer explained, thinking back to the moment he let go of Pitt in the water. We had a portrait of Pitt, too, with his favourite karaoke song (Sinatra's I've Got You Under My Skin) playing as Fitzgerald described him: "He was loud, loving and made a good cup of tea." This was a superb piece of radio: thoughtful, moving, richly textured and profound in the bigger questions it pondered.